ADELAIDE, Australia (AP) — Florent Serra of France beat Sweden's Joachim Johansson 2-6, 6-3, 6-4 Monday in a match between two former champions at the Australian men's hardcourt championship, which is experimenting with a round-robin format for the first time.

Peter Luczak upset fifth-seeded Dominik Hrbaty 6-3, 6-4 in one of three wins by Australian wild-card entries.

Former No. 1-ranked Lleyton Hewitt, made a return from injury in a doubles loss. He and fellow Australian Paul Hanley went down in straight sets to Czech pair Lukas Dlouhy and Pavel Vizner.

Hewitt starts his singles campaign on Tuesday against Serbia's Janko Tipsarevic. Third-seeded Radek Stepanek takes on Vincent Spadea and second-seeded Richard Gasquet plays Florian Mayer in other Tuesday matches, while Hrbaty faces American Paul Goldstein in his second round-robin match.

The 32-player Adelaide tournament is the first to try the ATP Tour's new round-robin format in 2007.

A dozen other tournaments are expected to experiment with the format during the season.

"For the players coming off their end-of-season break, the first match back is always tough," said co-tournament director Peter Johnston. "Now they know that they'll be assured of at least two matches during the crucial buildup period to the Australian Open."

Luczak said it eased the pressure a little bit.

"Early in the year you haven't been playing many matches — you've had a couple of months off — so it's good to know you've got at least two matches. I knew either way I'd get another match even if I lost so that does ease the pressure a bit."